...and looks like I wasn't the only one.
Chow wasn't unproven and he unofficially was a co-coordinator for years with Roger French. Chow called all the plays on offense starting back in 1982 so he was a primary contributor to some of the most successful offenses in BYU history and for the National Championship season in 1984. He was definitely a proven commodity and being given the title of OC was just a formality.
As for Scovil, he had been a college HC as well as a QB Coach in the NFL previously before coming to BYU. He was definitely a proven commodity as well.